Domestication Syndrome” in Light of Genomic Data

Total Page:16

File Type:pdf, Size:1020Kb

Domestication Syndrome” in Light of Genomic Data Вавиловский журнал генетики и селекции. 2017;21(4):435­442 Эволюционная генетика DOI 10.18699/VJ17.262 ОБЗОР / REVIEW Revisiting two hypotheses on the “domestication syndrome” in light of genomic data A.S. Wilkins Institute of Theoretical Biology, Humboldt Universität zu Berlin, Berlin, Germany Domesticated mammals of many different species share a set of «Синдром одомашнивания» physical and physiological traits that are not displayed by any of their wild progenitors. This suite of traits, now termed the “domestication в свете геномных данных syndrome” (DS), has been a puzzle since Charles Darwin discovered it. Two general explanations of its basis have been proposed, which in А.С. Уилкинс principle, could also apply to other vertebrates, such as fish and birds, whose domesticated varieties show some of its elements. The two Институт теоретической биологии Берлинского ideas are termed here, respectively, the thyroid hormone hypothesis университета им. Гумбольдта, Берлин, Германия or the THH, and the neural crest cell hypothesis, the NCCH. The two ideas make distinctly different genetic predictions. Here, the current relevant evidence from genomics is evaluated and it is concluded that Доместицированные млекопитающие разных видов the NCCH has more support. Nevertheless, one set of observations, имеют общий набор физических и физиологических from chickens, suggest a potentially important role of altered thyroid признаков, которых не было у их диких предков. metabolism in domestication. In addition, recent studies indicate the Совокупность этих признаков, называемая «синдро­ possibility of additional genetic factors in domestication, affecting мом одомашнивания», остается загадкой со времен tameness and sociality, that may go beyond either hypothesis. The Чарльза Дарвина, открывшего этот феномен. В на­ tasks that lie ahead to fully ascertain the genetic bases of the “domes­ стоящее время существуют две общие гипотезы, tication syndrome” and the behaviors that characterize mammalian объясняющие это явление, которые отчасти при­ domestication are discussed briefly. менимы и к другим позвоночным, например рыбам и птицам. Одну из этих гипотез мы называем гипоте­ Key words: animal domestication; “domestication syndrome”; Charles зой тиреоидных гормонов (THH), а другую – гипо­ Darwin; comparative genomics; neoteny; neural crest cells; thyroid тезой клеток нервного гребня (NCCH). Каждая из metabolism. гипотез приводит к совершенно разным выводам на уровне генетики. Основываясь на анализе по­ следних данных геномных исследований, имеющих отношение к обсуждаемому вопросу, мы пришли к выводу, что более обоснованной выглядит гипотеза NCCH. Тем не менее ряд наблюдений, сделанных на курах, указывает на потенциально важную роль из­ мененного метаболизма тиреоидных гормонов для процесса одомашнивания. Кроме того, недав ние исследования указывают на возможность существо­ вания дополнительных факторов одомашнивания, оказывающих влияние на приручаемость и социаль-­ ность и не учитываемых ни одной из рассматрива­ емых гипотез. Кратко обсуждаются задачи, направ­ ленные на выявление генетических основ «синдро­ ма одомашнивания» и особенностей поведения, специфичных для процесса одомашнивания млеко­ питающих. Ключевые слова: одомашнивание животных; «син­ дром одомашнивания»; Чарльз Дарвин; сравни­ тельная геномика; неотения; клетки нервного КАК ЦИТИРОВАТЬ ЭТУ СТАТЬЮ: гребня; метаболизм тиреоидных гормонов. Уилкинс А.С. «Синдром одомашнивания» в свете геномных данных. Вавиловский журнал генетики и селекции. 2017;21(4):435­442. DOI 10.18699/VJ17.262 HOW TO CITE THIS ARTICLE: Wilkins A.S. Revisiting two hypotheses on the “domestication syndrome” in light of genomic data. Vavilovskii Zhurnal Genetiki i Selektsii = Vavilov Jour­ nal of Genetics and Breeding. 2017;21(4):435­442. DOI 10.18699/VJ17.262 УДК 591.612:577.175.44 Поступила в редакцию 09.03.2017 г. Принята к публикации 10.05.2017 г. © АВТОР, 2017 e­mail: [email protected] he domestication of animals and, in particular, that of it): Charles Darwin. He had been trying to develop a theory various mammalian species, was crucial for the develop- of the nature of heredity since at least the early 1850s and in Tment of human civilizations (Diamond, 1999; Larson et 1868 published his monumental work on heredity, Variation al., 2014; Francis, 2015). Involving more than 20 mammalian of Animals and Plants under Domestication (Darwin, 1868). species, and a few bird and fish species, animal domestica- Darwin was writing decades before there was an experimental tion commenced in different places on different continents science of genetics, or even any kind of theoretical framework at different times but took place primarily during the past for understanding biological inheritance, and he had to rely 11–10,000 years, following the rise of agriculture (see Larson on the work of animal and plant breeders for the data he col- et al., 2014, Fig. 1). (The dog is one species, however, whose lected. In the course of compiling all the information for his initial domestication took place considerably earlier, and per- monumental work on heredity, he noticed that domesticated haps twice, independently, probably more than 15,000 years breeds, regardless of species, tended to share a common set of ago (Frantz et al., 2016).) visible traits, most of those listed above. (The physiological Given the historical importance of the domestication of traits of the DS were discovered much later, however.) mammals, it is of great interest to understand both its historical There are two particularly puzzling aspects of the condition. roots and its biological basis. Although there are many specific First is the variety of the different traits of the DS, which share questions about the histories of the different domestication little immediate obvious connection with each other. Second is events, the places and approximate dates for many species are the fact that the initial selection in each instance of domestica- increasingly well known (Larson et al., 2014; Francis, 2015). tion was almost certainly for tameness, permitting humans to The biology underlying domestication, however, presents a get close to the animals involved. (This pertains even to the major puzzle. Although the domestication of each species must evolution of dogs from wolves, where there may not have been have involved direct or indirect selection for docility (lack deliberate taming by humans but a self-selection of individual of fear) and tameness (ability to be handled by humans), the animals who neither attacked nor fled from people around domesticated breeds of the different mammalian species all human settlements.) The other traits were apparently dragged share a distinctive suite of physical and physiological traits, along as consequences of the initial selection, through poorly not seen in their wild progenitors. The suite of traits is neither understood connections. This phenomenon, in which selection universal amongst species nor amongst all breeds of a given for one trait brings in train one or more additional, unexpected species (Sanchez-Villagra et al., 2016). Nevertheless, it is traits, Darwin termed “unconscious selection” though perhaps sufficiently generic to be seen as a signature feature of mam- “unintended co-selection” might be more apt. malian domestication. The relationship of these traits to the Darwin’s own explanation of the phenomenon was neither initial selected traits of docility and tameness, however, is not totally self-consistent nor complete. He wanted to ascribe these readily apparent. The particular secondary morphological and changes to the gentler “conditions of living” provided by the physiological traits that mark the domesticated state include: anthropogenic environment but he also realized that in many floppy ears, smaller jaws, smaller teeth, pigmentation changes cases, the characteristics were or had become heredity, hence in the coats (toward white and brown spots), reductions in not solely a function of the anthropogenic environment. Fur- adrenocortical hormone titers, increased frequency of estrus thermore, he could not explain why the particular traits seen, cycles, reduction in brain size, and alterations in concentration and not others, were the ones that appeared in association with of several brain neurotransmitters. (For a comprehensive tally the domesticated state. It is, of course, not puzzling that he of which domestication-specific traits appear in the different himself could not answer the question in the 19th century, even mammalian species that have been domesticated, see Figure 1 approximately, given the general ignorance of Mendel’s work, of Sanchez-Villagra et al., 2016.) which would eventually provide the foundations of modern This condition has been dubbed the “domestication syn- genetics. What is perhaps more surprising in retrospect is that drome”, abbreviated here as the DS. The term itself appears 20th century genetics also failed to solve the problem. Some to have been first used in connection with a parallel set of heroic and important large efforts were made, however, and observed commonalities amongst domesticated plants (Ham- a significant start was made with the work of the pioneering mer, 1984) but was later applied to animals (Larson et al., Soviet geneticist Dmitry Belyaev and his colleagues from the 2014; Wilkins et al., 2014). (Some authors, however, prefer early 1960s onwards (Belyaev, 1974, 1979; reviewed in Trut the term “domesticated phenotype” to avoid the implication et
Recommended publications
  • Maladaptation in Feral and Domesticated Animals
    Nova Southeastern University NSUWorks Biology Faculty Articles Department of Biological Sciences 8-2019 Maladaptation in Feral and Domesticated Animals Eben Gering Michigan State University, [email protected] Darren Incorvaia Michigan State University R. Henriksen Linkoping University- Sweden Dominic Wright Linkoping University- Sweden Follow this and additional works at: https://nsuworks.nova.edu/cnso_bio_facarticles Part of the Biology Commons NSUWorks Citation Gering, Eben; Darren Incorvaia; R. Henriksen; and Dominic Wright. 2019. "Maladaptation in Feral and Domesticated Animals." Evolutionary Applications 12, (7): 1274-1286. doi:10.1111/eva.12784. This Article is brought to you for free and open access by the Department of Biological Sciences at NSUWorks. It has been accepted for inclusion in Biology Faculty Articles by an authorized administrator of NSUWorks. For more information, please contact [email protected]. Received: 17 October 2018 | Revised: 10 January 2019 | Accepted: 7 February 2019 DOI: 10.1111/eva.12784 SPECIAL ISSUE REVIEW AND SYNTHESES Maladaptation in feral and domesticated animals Eben Gering1 | Darren Incorvaia1 | Rie Henriksen2 | Dominic Wright2 | Thomas Getty1 1Department of Integrative Biology and Ecology, Evolutionary Biology, and Behavior Abstract Program, Michigan State University, East Selection regimes and population structures can be powerfully changed by domesti‐ Lansing, Michigan cation and feralization, and these changes can modulate animal fitness in both cap‐ 2IIFM Biology and AVIAN Behavioural Genomics and Physiology Group, Linköping tive and natural environments. In this review, we synthesize recent studies of these University, Sweden two processes and consider their impacts on organismal and population fitness. Correspondence Domestication and feralization offer multiple windows into the forms and mecha‐ Eben Gering, Department of Integrative nisms of maladaptation.
    [Show full text]
  • The Evolution of Animal Domestication
    See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/266740619 The Evolution of Animal Domestication Article in Annual Review of Ecology Evolution and Systematics · October 2014 DOI: 10.1146/annurev-ecolsys-120213-091620 CITATIONS READS 179 3,162 2 authors: Greger Larson Dorian Q Fuller University of Oxford University College London 196 PUBLICATIONS 6,523 CITATIONS 322 PUBLICATIONS 12,021 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Dog Domestication View project Rwandan Archaeology View project All content following this page was uploaded by Dorian Q Fuller on 12 October 2014. The user has requested enhancement of the downloaded file. ES45CH06-Larson ARI 16 September 2014 11:18 V I E E W R S I E N C N A D V A The Evolution of Animal Domestication Greger Larson1 and Dorian Q. Fuller2 1Durham Evolution and Ancient DNA, Department of Archaeology, Durham University, Durham, DH1 3LE, United Kingdom; email: [email protected] 2Institute of Archaeology, University College London, London WC1H 0PY, United Kingdom Annu. Rev. Ecol. Evol. Syst. 2014. 66:115–36 Keywords The Annual Review of Ecology, Evolution, and archaeology, genetics, livestock, introgression, selection, agriculture Systematics is online at ecolsys.annualreviews.org This article’s doi: Abstract 10.1146/annurev-ecolsys-120213-091620 The domestication of plants and animals over the past 11,500 years has Copyright c 2014 by Annual Reviews. had a significant effect not just on the domesticated taxa but also on human All rights reserved evolution and on the biosphere as a whole.
    [Show full text]
  • Archaeological Central American Maize Genomes Suggest Ancient Gene Flow from South America
    Archaeological Central American maize genomes suggest ancient gene flow from South America Logan Kistlera,1, Heather B. Thakarb, Amber M. VanDerwarkerc, Alejandra Domicd,e, Anders Bergströmf, Richard J. Georgec, Thomas K. Harperd, Robin G. Allabyg, Kenneth Hirthd, and Douglas J. Kennettc,1 aDepartment of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560; bDepartment of Anthropology, Texas A&M University, College Station, TX 77843; cDepartment of Anthropology, University of California, Santa Barbara, CA 93106; dDepartment of Anthropology, The Pennsylvania State University, University Park, PA 16802; eDepartment of Geosciences, The Pennsylvania State University, University Park, PA 16802; fAncient Genomics Laboratory, The Francis Crick Institute, NW1 1AT London, United Kingdom; and gSchool of Life Sciences, University of Warwick, CV4 7AL Coventry, United Kingdom Edited by David L. Lentz, University of Cincinnati, Cincinnati, OH, and accepted by Editorial Board Member Elsa M. Redmond November 3, 2020 (received for review July 24, 2020) Maize (Zea mays ssp. mays) domestication began in southwestern 16). However, precolonial backflow of divergent maize varieties Mexico ∼9,000 calendar years before present (cal. BP) and humans into Central and Mesoamerica during the last 9,000 y remains dispersed this important grain to South America by at least 7,000 understudied, and could have ramifications for the history of cal. BP as a partial domesticate. South America served as a second- maize as a staple in the region. ary improvement center where the domestication syndrome be- Morphological evidence from ancient maize found in ar- came fixed and new lineages emerged in parallel with similar chaeological sites combined with DNA data confirms a complex processes in Mesoamerica.
    [Show full text]
  • The History of Farm Foxes Undermines the Animal Domestication Syndrome, Trends in Ecology & Evolution (2019)
    Please cite this article in press as: Lord et al., The History of Farm Foxes Undermines the Animal Domestication Syndrome, Trends in Ecology & Evolution (2019), https://doi.org/10.1016/j.tree.2019.10.011 Trends in Ecology & Evolution Opinion The History of Farm Foxes Undermines the Animal Domestication Syndrome Kathryn A. Lord,1,2 Greger Larson,3,@ Raymond P. Coppinger,4,6 and Elinor K. Karlsson1,2,5,@,* The Russian Farm-Fox Experiment is the best known experimental study in animal domestication. Highlights By subjecting a population of foxes to selection for tameness alone, Dimitry Belyaev generated The ‘domestication syndrome’ has foxes that possessed a suite of characteristics that mimicked those found across domesticated been a central focus of research species. This ‘domestication syndrome’ has been a central focus of research into the biological into the biological processes un- pathways modified during domestication. Here, we chart the origins of Belyaev’s foxes in derlying domestication. The eastern Canada and critically assess the appearance of domestication syndrome traits across an- Russian Farm-Fox Experiment was imal domesticates. Our results suggest that both the conclusions of the Farm-Fox Experiment the first to test whether there is a and the ubiquity of domestication syndrome have been overstated. To understand the process causal relationship between selec- tion for tameness and the domes- of domestication requires a more comprehensive approach focused on essential adaptations to tication syndrome. human-modified environments. Historical records and genetic The Origins of Domestication Syndrome analysis show that the foxes used in The domestication syndrome describes a suite of behavioral and morphological characteristics the Farm-Fox Experiment origi- consistently observed in domesticated populations.
    [Show full text]
  • Hered 445 Master..Hered 445 .. Page648
    Heredity 81 (1998) 648–658 Received 19 March 1998, accepted 15 June 1998 Genetic analysis of the domestication syndrome in pearl millet (Pennisetum glaucum L., Poaceae): inheritance of the major characters V. PONCET*%, F. LAMY%, J. ENJALBERT^, H. JOLY§, A. SARR% & T. ROBERT% %Laboratoire d’Evolution et Syst´ematique, Universit´e Paris XI, Bˆat. 362, F-91405 Orsay Cedex, France, ^Station de G´en´etique V´eg´etale, Ferme du Moulon, F-91190 Gif sur Yvette, France and §CIRAD-Forˆet, campus international de Baillarguet, BP 5035, F-34032 Montpellier Cedex 1, France The inheritance of domestication traits distinguishing pearl millet (Pennisetum glaucum) from its wild relatives (P. mollissimum) was assessed in F2 progenies derived from a cross between a typical landrace of pearl millet and a wild ecotype. Despite a high level of recombination between the two genomes, the existence of preferential associations between some characters was demonstrated, leading, in particular, to cultivated-like phenotypes. Traits determining spikelet structure showed simple Mendelian inheritance. Moreover, the genes encoding these traits mapped in a linkage group where quantitative trait loci for spike size and tillering habit were found. This linkage group could correspond to one of the two chromosome segments that have already been shown to be involved in the variation for spikelet structure in progenies from several cultivatedÅwild crosses. A synthetic map of these two regions is given. The evolutionary significance of this genomic organization in relation to the domestication process is discussed, as well as its potential use for pearl millet genetic resources enhancement. Keywords: domestication, genetic map, pearl millet, Pennisetum glaucum.
    [Show full text]
  • UNIVERSITY of CALIFORNIA Los Angeles the Evolution of Animals Through Domestication and Other Human Relationships
    UNIVERSITY OF CALIFORNIA Los Angeles The Evolution of Animals through Domestication and other Human Relationships: An Animal-Centered Approach A thesis submitted in partial satisfaction of the requirements for the degree Master of Arts in Anthropology by Steven Michael Ammerman 2017 ©Copyright by Steven Michael Ammerman 2017 ABSTRACT OF THE THESIS The Evolution of Animals through Domestication and other Human Relationships: An Animal-Centered Approach by Steven Michael Ammerman Master of Arts in Anthropology University of California, Los Angeles, 2017 Professor Monica L. Smith, Chair As a component of the environment themselves, humans maintain a mutualistic modifying process with that environment. The interaction between humans and animals has led to different categories of relationships—commensal animals, tame animals, domesticated animals, and feral animals. In the study of human-animal interactions, the foremost consideration is how the niche construction of humans affects the evolutionary trajectory of other animals, but other animals also construct niches within this human-impacted environment to enhance their survival. The concept of niche construction provides a useful way of thinking about how humans and animals interact in the environment because this concept considers physical changes, behavioral changes, and cultural changes. In an animal-centered approach, consideration of how the traits and actions of animals play an active role in allowing and encouraging their ongoing relationships with humans is just as important as the consideration of actions of humans. ii The thesis of Steven Michael Ammerman is approved. Nancy E. Levine P. Jeffrey Brantingham Monica L. Smith, Committee Chair University of California, Los Angeles 2017 iii Table of Contents 1.
    [Show full text]
  • Paleogenomics of Animal Domestication
    Paleogenomics of Animal Domestication Evan K. Irving-Pease, Hannah Ryan, Alexandra Jamieson, Evangelos A. Dimopoulos, Greger Larson, and Laurent A. F. Frantz Abstract Starting with dogs, over 15,000 years ago, the domestication of animals has been central in the development of modern societies. Because of its importance for a range of disciplines – including archaeology, biology and the humanities – domestication has been studied extensively. This chapter reviews how the field of paleogenomics has revolutionised, and will continue to revolutionise, our under- standing of animal domestication. We discuss how the recovery of ancient DNA from archaeological remains is allowing researchers to overcome inherent shortcom- ings arising from the analysis of modern DNA alone. In particular, we show how DNA, extracted from ancient substrates, has proven to be a crucial source of information to reconstruct the geographic and temporal origin of domestic species. We also discuss how ancient DNA is being used by geneticists and archaeologists to directly observe evolutionary changes linked to artificial and natural selection to generate a richer understanding of this fascinating process. Keywords Ancient DNA · Archaeology · Domestication · Entomology · Evolution · Genomics · Zoology E. K. Irving-Pease (*) · H. Ryan · A. Jamieson · E. A. Dimopoulos · G. Larson The Palaeogenomics and Bio-Archaeology Research Network, Research Laboratory for Archaeology and History of Art, University of Oxford, Oxford, UK e-mail: [email protected] L. A. F. Frantz (*) The Palaeogenomics and Bio-Archaeology Research Network, Research Laboratory for Archaeology and History of Art, University of Oxford, Oxford, UK School of Biological and Chemical Sciences, Queen Mary University of London, London, UK e-mail: [email protected] Charlotte Lindqvist and Om P.
    [Show full text]
  • Awn Reduction and the Domestication of Asian Rice: a Syndrome Or Crop Improvement Trait? Serge Svizzero, Avik Ray, Debarati Chakraborty
    Awn Reduction and the Domestication of Asian Rice: A Syndrome or Crop Improvement Trait? Serge Svizzero, Avik Ray, Debarati Chakraborty To cite this version: Serge Svizzero, Avik Ray, Debarati Chakraborty. Awn Reduction and the Domestication of Asian Rice: A Syndrome or Crop Improvement Trait?. Economic Botany, Springer Verlag, 2019, pp.1-12. 10.1007/s12231-019-09465-0. hal-02275855 HAL Id: hal-02275855 https://hal.univ-reunion.fr/hal-02275855 Submitted on 2 Sep 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. 1 Awn Reduction and the Domestication of Asian Rice: A Syndrome or Crop Improvement Trait? Serge Svizzero1, Avik Ray2,*, Debarati Chakraborty2,3 1- Faculté de Droit et d’Economie, Université de La Réunion, 15 Avenue René Cassin. CS 92003, 97744 Saint Denis Cedex 9, France, Tel: +262 262 13 82 58; ORCID: 0000-0003- 3895-7273 2 - Center for studies in Ethnobiology, Biodiversity, and sustainability (CEiBa), B.G. Road, Mokdumpur, Malda – 732103, West Bengal, India; ORCID: 0000-0003-1662-7679 3 - Department of Molecular Biology and Biotechnology, University of Kalyani, Kalyani, India; ORCID: 0000-0002-1939-9889 * [email protected] Running title: SVIZZERO, RAY AND CHAKRABORTY: RICE AWN REDUCTION Words account: 7596; Abstract: 180.
    [Show full text]
  • Animal Domestication in the Era of Ancient Genomics Laurent Frantz, Daniel Bradley, Greger Larson, Ludovic Orlando
    Animal domestication in the era of ancient genomics Laurent Frantz, Daniel Bradley, Greger Larson, Ludovic Orlando To cite this version: Laurent Frantz, Daniel Bradley, Greger Larson, Ludovic Orlando. Animal domestication in the era of ancient genomics. Nature Reviews Genetics, Nature Publishing Group, 2020, 21 (8), pp.449-460. 10.1038/s41576-020-0225-0. hal-03030302 HAL Id: hal-03030302 https://hal.archives-ouvertes.fr/hal-03030302 Submitted on 30 Nov 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Animal domestication in the era of ancient genomics Laurent A. F. Frantz1†, Daniel G. Bradley2, Greger Larson3 and Ludovic Orlando4,5† 1 School of Biological and Chemical Sciences, Queen Mary University of London, London, UK. 2 Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland 3 The Palaeogenomics & Bio-Archaeology Research Network, Research Laboratory for Archaeology and History of Art, The University of Oxford, Oxford, UK. 4 Laboratoire d’Anthropobiologie Moléculaire et d’Imagerie de Synthèse, CNRS UMR 5288, Université de Toulouse,
    [Show full text]
  • 1 the Limits of Selection Under Plant Domestication Robin G Allaby1
    The limits of selection under plant domestication Robin G Allaby1* ,Dorian Q Fuller2, James L Kitchen1, 3 1. School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry CV4 7AL 2. Institute of Archaeology, University College London, 31-34 Gordon Square, London WC1H 0PY 3. Computational and Systems Biology, Rothamsted, Harpenden, Herts. * corresponding author email: [email protected] 1 Abstract Plant domestication involved a process of selection through human agency of a series of traits collectively termed the domestication syndrome. Current debate concerns the pace at which domesticated plants emerged from cultivated wild populations and how many genes were involved. Here we present simulations that test how many genes could have been involved by considering the cost of selection. We demonstrate the selection load that can be endured by populations increases with decreasing selection coefficients and greater numbers of loci down to values of about s = 0.005, causing a driving force that increases the number of loci under selection. As the number of loci under selection increases, an effect of co-selection increases resulting in individual unlinked loci being fixed more rapidly in out-crossing populations, representing a second driving force to increase the number of loci under selection. In inbreeding systems co-selection results in interference and reduced rates of fixation but does not reduce the size of the selection load that can be endured. These driving forces result in an optimum pace of genome evolution in which 50-100 loci are the most that could be under selection in a cultivation regime. Furthermore, the simulations do not preclude the existence of selective sweeps but demonstrate that they come at a cost of the selection load that can be endured and consequently a reduction of the capacity of plants to adapt to new environments, which may contribute to the explanation of why selective sweeps have been so rarely detected in genome studies.
    [Show full text]
  • The Molecular Basis of Kale Domestication: Transcription Profiling of Leaves
    bioRxiv preprint doi: https://doi.org/10.1101/2020.11.25.398347; this version posted December 2, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Arias et al., p. 1 1 2 Running head: Kale domestication 3 4 The molecular basis of Kale domestication: Transcription profiling of leaves 5 and meristems provides new insights into the evolution of a Brassica oleracea 6 vegetative morphotype 7 8 Tatiana Arias1,2,4*, Chad Niederhuth1,3,4, Paula McSteen1, J. Chris Pires1 9 10 11 1 Division of Biological Sciences, University of Missouri, Columbia, MO, United States 12 2 Current address: Tecnológico de Antioquia, Medellín, Colombia. 13 3 Current address: Department of Plant Biology, Michigan State University, East Lansing MI, 14 United States 15 4 Both authors contributed equally to this manuscript 16 17 *author for correspondence: [email protected] 18 19 Manuscript received _______; revision accepted _______. 20 Short title: Kale domestication 21 22 bioRxiv preprint doi: https://doi.org/10.1101/2020.11.25.398347; this version posted December 2, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Arias et al., p. 2 23 ABSTRACT [237 words - 250 max] 24 Morphotypes of Brassica oleracea are the result of a dynamic interaction between genes that 25 regulate the transition between vegetative and reproductive stages and those that regulate leaf 26 morphology and plant architecture.
    [Show full text]
  • Domestication Syndrome” in Mammals: a Unified Explanation Based on Neural Crest Cell Behavior and Genetics
    HIGHLIGHTED ARTICLE PERSPECTIVES The “Domestication Syndrome” in Mammals: A Unified Explanation Based on Neural Crest Cell Behavior and Genetics Adam S. Wilkins,*,†,1 Richard W. Wrangham,*,‡ and W. Tecumseh Fitch§ *Stellenbosch Institute of Advanced Study, Stellenbosch 7600, South Africa, †Institute of Theoretical Biology, Humboldt University zu Berlin, Berlin 10115, Germany, ‡Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, and §Department of Cognitive Biology, University of Vienna, A-1090 Vienna, Austria ABSTRACT Charles Darwin, while trying to devise a general theory of heredity from the observations of animal and plant breeders, discovered that domesticated mammals possess a distinctive and unusual suite of heritable traits not seen in their wild progenitors. Some of these traits also appear in domesticated birds and fish. The origin of Darwin’s “domestication syndrome” has remained a conundrum for more than 140 years. Most explanations focus on particular traits, while neglecting others, or on the possible selective factors involved in domestication rather than the underlying developmental and genetic causes of these traits. Here, we propose that the domestication syndrome results predominantly from mild neural crest cell deficits during embryonic development. Most of the modified traits, both morphological and physiological, can be readily explained as direct consequences of such deficiencies, while other traits are explicable as indirect consequences. We first show how the hypothesis can account for the multiple, apparently unrelated traits of the syndrome and then explore its genetic dimensions and predictions, reviewing the available genetic evidence. The article concludes with a brief discussion of some genetic and developmental questions raised by the idea, along with specific predictions and experimental tests.
    [Show full text]